The Internet could be ripe for an increase in controversial direct-to-consumer pharmaceutical marketing, as a recent DoubleClick study suggests that the medium is particularly suited to the model and advertising researchers are gearing up to better track the practice.

New York-based DoubleClick and its online ad agency, Beyond Interactive, said a recent study conducted on an prescription allergy drug manufacturer’s 15-month campaign found that Internet advertising proved the most cost-effective medium.

On the other hand, television, doctor calls and print ads each drove more sales, but accounted for a lower return on investment from marketing. TV, which accounted for 85 percent of the campaign’s impressions, accounted for about 12 percent of sales and 73 percent of prescriptions written due to advertising. But online advertising, which led to 1 percent of sales and accounted for only 3 percent of the campaign’s impressions, generated 7 percent of advertising-driven prescriptions.

Additionally, the Internet proved to be cheaper for generating incremental prescriptions than either TV or print. Those media proved 50 percent and 20 percent more expensive, respectively, than online — even though Internet ads necessitated higher spending per impression.

Extrapolating from the data, Beyond Interactive’s research unit said that had the television budget been decreased by 3.1 percent, and those dollars spent instead on increasing the Web spending by 50 percent, prescriptions would have increased slightly, by 0.1 percent.

“This is the first time that we are aware of modeling that includes online media for a non-dot-com and non-[consumer packaged goods] product,” said Michele Madansky of Beyond Interactive. “We are extremely happy to have developed this model which enables a major pharmaceutical to include online advertising in its reallocation scenarios. We expect many other companies to begin to adopt these tools to determine their optimum media mix.”

At the same time, two research groups unveiled a joint effort to better study the impact of online advertising on direct-to-consumer pharmaceutical marketing efforts.

Stamford, Conn.-based InsightExpress and Manhattan Research of New York this week launched pharmawebROI, an ad campaign and site effectiveness tool aimed at tracking and optimizing marketing spending by pharmaceutical clients.

Manhattan Research, which services 17 of the top 20 global pharma companies, will offer the service to its clients as an extension of its existing Cybercitizen Health syndicated research product. Interpublic-backed InsightExpress will handle surveys used in tracking campaign effectiveness.

“Together, InsightExpress and Manhattan Research will finally empower healthcare companies to understand the return on their Web and online marketing initiatives,” said Lee Smith, president and chief operating officer at InsightExpress.

As part of the multi-year partnership between the two research outfits, Manhattan Research will have access to InsightExpress’ lists of more than more than 100 million Internet users for surveys.

The effort to focus on tracking Internet marketing in the healthcare vertical comes amid a wider trend, as Web site and campaign analytics vendors look to beef up their services’ ability to track ROI, in response to marketers’ growing need to justify spending — especially when it comes to interactive investments.

The news from DoubleClick, InsightExpress and Manhattan Research highlights the growing prominence of direct-to-consumer pharmaceutical advertising, which bodes well for the beleaguered Internet space if it’s successful in making its pitch to drugmakers.

Marketing by pharma companies to consumers and physicians is believed to be growing, and ranged between $12 billion and $16 billion during the past year based on various estimates. According to the Harvard School of Public Health, DTC promotions represent only 15 percent of marketing expenses — demonstrating that there’s room to grow, considering that many such efforts have proven to be marketplace successes.

But some physicians’ groups and consumer advocates have been widely outspoken against DTC advertising since the Food and Drug Administration began allowing some forms of the practice in the late 90’s. Critics charge that advertising to consumers will increase drug prices, and that such efforts damage the doctor-patient relationship by encouraging relatively uninformed consumers to demand certain drugs from physicians who might normally be reluctant to do so.